Performance Analysis for Asynchronous Requests in Wireless Networks with Multiple Packet Reception Capability

An important key technology used in the new standard IEEE 802.11ax is a multiple-user multiple-input multiple-output (MU-MIMO) antenna technology. With MU-MIMO technology, a wireless access point (AP) can increase network throughput by simultaneously multiple packet reception (MPR) from wireless users. Using MPR capability, the new medium access control (MAC) protocol is proposed to allow wireless users transmitting packets at the same time and even when there is an ongoing transmission in the network. The new mechanism for transmission process allows users to transmit packets on two conditions; the time during first ongoing RTS frame transmission and the total ongoing users less than maximum MPR capability. In addition, the format of frame control is modified to identify the multiple packet transmission. For performance evaluation, the mathematical model is derived to calculate throughput and the probability of idle, success transmission, and collision of the network. Moreover, the results are validated by MATLAB program simulation. The results show that throughput obtained by the proposed protocol is about 40% higher than that obtained by the carrier sense multiple access with collision avoidance (CSMA/CA) protocol when the maximum MPR capability is two and the contention window size is sixty-four. Moreover, the probability of success transmission increases when the number of transmissions equals to the maximum MPR capability. Finally, to obtain high throughput, the contention window size should be optimized with the number of users and the maximum MPR capability.